The present invention relates to a passenger protection device configured to retract the webbing of a seatbelt using an electric motor. More particularly the present invention relates to a technology for controlling the retraction of the webbing in accordance with the Situation.
Japanese Laid-Open Patent Publication No. 2001-253317 discloses a passenger restraining device to determine if an emergency situation exists in which there is the possibility that the vehicle in which the passenger restraining device is installed will come abnormally close to a preceding vehicle or an obstacle and, if such an emergency situation exists, to retract the seatbelt using an electric motor. The passenger restraining device uses information regarding the operation of the brakes by the driver while driving (e.g., depression of the brake pedal, brake fluid pressure) in order to determine if such an emergency situation exists.
Additionally, Japanese Laid-Open Patent Publication No. 2000-190815 discloses a technology provided with a belt control device configured to control the belt tension of a seatbelt in accordance with the driving conditions of the vehicle and belt wearer status detecting means to detect the posture of a passenger wearing a seatbelt, the belt tension control being executed based on information indicating the detected posture of the belt wearer. With that technology, when the belt wearer is the driver of the vehicle, the device controls the seatbelt tension in such a manner that the seatbelt tension increases as a quantity expressing a vehicle driving operation (e.g., brake pedal depression speed, brake pedal depression force, steering operating angle, etc.) increases, said quantity being detected and provided as vehicle state detection information.